Neuroimaging Core The Neuroimaging Core builds upon a strong foundation developed over the past four years as a STRONG STAR core. Dr. Fox is currently Director of the STRONG STAR Neuroimaging Core; he will continue in this role for the STRONG STAR-CAP, being joined by Dr. Krystal as Co-Director. The overall objective of the Neuroimaging Core is to foster the use of advanced neuroimaging methods in the study of PTSD and related conditions for the purposes of (1) investigating the underlying pathology (using structural imaging) and pathophysiology (using functional imaging); (2) assessing and enhancing the diagnostic sensitivity of imaging methods; (3) investigating the neurophysiology of treatment response (image-based response assessment); and (4) ensuring comparability of imaging data acquisition and pre-processing between sites. Neuroimaging methods utilized include structural and functional magnetic resonance imaging (MRI and fMRI), magnetic resonance spectroscopy (MRS), and position emission tomography (PET). These methods are used in the context of extensive neurocognitive assessments focused on evaluation of PTSD-related impairments, with psychometric scores being used as probes for voxel-wise and region-of-interest-based analyses. The Neuroimaging Core provides standardized core image-acquisition and image-analysis protocols (both structural and functional), as well as developing project-specific neuroimaging probes. In the ongoing STRONG STAR Consortium, neuroimaging imaging assessments focused on modeling the system-level effects of PTSD (e.g., Ramage et al., 2012) and characterizing the mechanisms of action of cognitive and behavioral therapy. In the current proposal, emphasis is placed on the mechanisms of action of Prolonged Exposure (PE; project 1), on pharmacotherapy (ketamine; Project 1) and on insomnia (Project 7). Previously based solely at UTHSCSA's Research Imaging Institute, the Neuroimaging Core now incorporates a second world-class neuroimaging facility, i.e., that at Yale. In doing so, the Neuroimaging Core builds upon an ongoing collaborative relationship with Yale, focused on high-field, small-animal imaging. Image-analysis capabilities at both core components are outstanding and complementary, with the Research Imaging Institute having exceptional strengths in meta- analysis and system-level modeling construction and with Yale having exceptional strengths in analysis of pharmacologic interventions and tracer-based imaging methods.